Is it bad to charge an EV to 100%?

Charging to 100% now and then is fine for most EVs, but leaving the battery full for long periods wears it faster. Battery University estimates a lithium-ion battery stored for a year at 25°C keeps 96% of its capacity at 40% charge, but only 80% at 100% charge.

Battery University's guide to prolonging lithium batteries says high voltage and dwelling at full charge stress the cells, and that EVs typically limit charge to 85% and discharge to 25% to protect battery life. Follow your carmaker's advice, since the right daily limit varies by car.

Charging to 100% on a DC fast charger also takes much longer, because power drops as the battery fills. The guide to the EV charging curve explains why. Setting a daily limit below full and charging to 100% before a long trip is a common pattern.